The problem of grain-storage explosions has been very serious for many years. Grain dust is released from the grain during transport and handling of the grain. When the dust is confined, as in a grain storage elevator, it can ignite, causing an explosion. Such explosions have resulted in substantial loss of human life and of property, and, until now, no effective solution has been found to the problem.
Howard W. Cole, Jr. has invented a machine and method for making small bubble foam having bubble diameters from 50 to 200 microns when first ejected from the foam generator as described in U.S. Pat. Nos. 3,811,660 and 4,400,220, which are hereby incorporated by reference. A third Cole patent, U.S. Pat. No. 4,207,202, describes an improved version of the foam generator and is also hereby incorporated by reference. In those patents, in order to make suitable foam for dust suppression, air, water and surfactant are pumped through tortuous passages to form very small bubbles as explained in those patents. Unfortunately, until now, we have not been able to apply small bubble foam to grain or other food products, because the surfactants used to make the small bubble foam wire not approved for use with food.